Blocking device for the carriage of typewriters and similar machines

ABSTRACT

A device for blocking the carriage of typewriters and similar machines during the performance of line shifts has a switching bar which can be displaced in the direction of the movement of the carriage and is mounted to be pivoted in a direction perpendicular to the movement of the carriage. This switching bar is operable to be actuated by the line-shift key, and is provided with a blocking member defining a plurality of open slots engageable with a plurality of stop members on the carriage to block the carriage. A push rod is also provided on the switching bar which is operable to interrupt the carriage return movement. Once the carriage return movement is interrupted, the switching bar is returned to its rest position by a suitable tension spring.

United States Patent Kunst 51 Oct. 24, 1972 [54] BLOCKING DEVICE FOR THE CARRIAGE OF TYPEWRITERS AND 21 App1.No.: 35,661

[30] Foreign Application Priority Data May 14, 1969 Germany ..P 19 24 601.6

[52] US. Cl. ..197/120, 197/66, 197/176, 197/193 [51] Int. Cl. ..B4lj 19/90 [58] Field of Search ..197/65, 66, 67, 68, 107, 108, 197/109,110,111,1l2,114,176, 120,193

[56] References Cited UNITED STATES PATENTS 3,151,725 10/1964 Link ..197/176 2,104,007 1/1938 Bower ..197/66 1,143,404 6/1915 Kennedy ..197/66 1,757,516 5/1930 Degener ..197/114 2,262,676 1 1/1941 l-lelmond 197/66 2,904,158 9/1959 Hess ..197/66 2,919,006 12/1959 Hess et a1. .,197/66 2,958,407 11/1960 Hess ..197/66 3,048,252 8/ 1962 Chamberlain et a1. ..197/66 FOREIGN PATENTS OR APPLICATIONS 1,142,179 1/1963 Germany ..197/114 1,142,370 1/1963 Germany ..197/120 720,192 12/1954 Great Britain ..197/193 Primary Examiner-Emest T. Wright, Jr. Att0rneySpencer & Kaye [57] ABSTRACT A device for blocking the carriage of typewriters and similar machines during the performance of line shifts has a switching bar which can be displaced in the direction of the movement of the carriage and is mounted to be pivoted in a direction perpendicular to the movement of the carriage. This switching bar is operable to be actuated by the line-shift key, and is provided with a blocking member defining a plurality of open slots engageable with a plurality of stop members on the carriage to block the carriage. A push rod is also provided on the switching bar which is operable to interrupt the carriage return movement. Once the carriage return movement is interrupted, the switching bar is returned to its rest position by a suitable tension spring.

2 Claims, 2 Drawing Figures PATENTEUUCT 24 I972 WVENTOR Deflef Kunsz ATTOR NEYS.

BLOCKING DEVICE FOR THE CARRIAGE OF TYPEWRITERS AND SIMILAR MACHINES BACKGROUND OF THE INVENTION bles, to perform one or more line shifts without retuming the carriage into its left-margin position.

In order to achieve this, devices have become known which bring a locking pawl into position when actuated by means of a special key to block the carriage. In this case, the carriage moves slightly past the abutment position into the so-called overshoot position and the drive means for returning the carriage is interrupted.

These embodiments have the disadvantage, however, that they are relatively complicated and include a plurality of individual elements whose adjustment is very sensitive.

A further and more important disadvantage of the known devices is that the carriage is moved into the overshoot position and back to its abutment position each time there is a line shift, and this movement causes annoying switching noises.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a device for blocking the carriage of typewriters and similar machines during the performance of line shifts which eliminates the disadvantages mentioned above and which is particularly distinguished by its simplicity and dependability.

This and other objects are accomplished according to the present invention by providing a comb-shaped blocking member which is actuated by depressing a key to bring the carriage into a blocked condition by means of a connecting member. The blocking member is attached to a switching bar which can be displaced in the direction of the movement of the carriage and which is mounted for pivotal movement in a direction perpendicular to the direction of movement of the carriage.

A particularly significant feature of the present invention is that the blocking member preferably is constructed of a synthetic material.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view, partly in cross section, showing the blocking device of the present invention in its rest position.

FIG. 2 is a perspective view, partly in cross section, showing the blocking device of the present invention in its operative position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a device including a connecting rod 1 which is operatively connected to a known line shift key (not shown) and pivotally connected to a switching bar 2 by means of a crank 2c. A bearing bracket 3 is attached to the machine housing, as by bolts 11, and presents openings for mounting a shaft 4 in a well known manner. Switching bar 2 is mounted on shaft 4 so that it can pivot in a direction A perpendicular to the direction B of movement of the carriage, and can be displaceable in the direction B of movement of the carriage. A push rod 2a extends outwardly from, and is integral with, switching bar 2 in the direction B of movement of the carriage. A bore 2d is provided near the outward end of push rod 2a for mounting one end of a suitable tension spring 5. The other end of spring 5 is attached to flange 3 of bracket 3.

The distance between the portions of bearing bracket 3 provided with the shaft carrying openings is made somewhat greater than the length of the main body of bar 2 in order to permit bar 2 to undergo a predetermined amount of axial movement. A blocking member 6 is attached to an arm 2b which extends outwardly from, and is integral with, switching bar 2 in a direction perpendicular to the direction B of movement of the carriage. Blocking member 6 has slots along one of its edges to form a plurality of teeth 6a. These slots and teeth 6a are dimensioned to cooperate with suitable stop elements, such as stops 8, which are, for example, tabulator stops, mounted on a known stop bar 7. Stop bar 7 is attached to the carriage so as to move therewith. The blocking member 6 is constructed from a sound absorbing synthetic material.

A shaft 9 is mounted to extend transversely to the direction B of the carriage movement. A switching lever 10 is mounted for pivotal movement on shaft 9, and is in operative connection with a known drive means for returning the carriage. The push rod 2a is arranged so as to be in operative connection with switching lever 10 for pivoting lever 10 so as to deactivate the carriage return drive means.

A so-called line-shift key (not shown) is provided to positively effect a line shift without returning the carriage to its left-margin position. This line-shift key is in addition to the carriage return key, and is well known in the art.

When the line-shift key is depressed, connecting rod 1 is moved in the direction of the arrow A in FIG. 1, so that the switching bar 2 is pivoted counterclockwise around shaft 4 by means of the crank 2c. This counterclockwise pivoting of the switching bar 2 brings the teeth 6a of the blocking member 6 into engagement with the stops 8 on bar 7 (FIG. 2). When the line-shift key is depressed, the drive means for the carriage return is actuated. The carriage then attempts to move toward the left-margin position and carries the bar 7 with stops 8 along with it. Stops 8 are now in engagement with teeth 6a of blocking member 6, however, and move switching bar 2 in the same direction as the carriage is moving (Arrow B). This latter movement brings the push rod 2a of switching bar 2 into contact with the bent switching lever 10 and pivots lever 10 counterclockwise (Arrow C of FIG. 1) so that the drive means for the carriage return is switched off (FIG. 2).

The interruption of the carriage return drive means is carried out in less than one space division of the machine, this being sufficient for switching lever 10 to perform its function.

Once the line-shift key is released, the switching bar 2 performs a clockwise pivoting movement due to the biasing of spring 5. This moves the teeth 6a of the blocking member 6 out of engagement with the stops 8, and the switching bar 2 returns to its rest position of FIG. 1.

The present invention is not limited only to the described embodiment, but can be modified in various ways. If, for example, the tabulator stops 8 can not be used for this blocking function for some reason, it is possible to use the available carriage bar or a specially provided toothed bar for this purpose.

It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.

I claim:

1. Apparatus for blocking the movement of the carriage of typewriters and similar machines during the performance of line shifts, comprising: carriage stop means mounted to the carriage; a switching bar provided with a push rod extending outwardly in the direction of movement of the carriage and a blocking member having an open slot; means for biasing said switching bar into a rest position; connecting means connected to said switching bar and operatively connected to a line shift actuator for moving said switching bar away from said rest position and into an operative position and for actuating the carriage return movement; means mounting said switching bar to the machine for a displacement of less than one character space division of the machine in the direction of movement of the carriage and for movement with respect to said stop means into said operative position only when said carriage is stationary for engaging said stop means in said open slot to block the movement of the carriage, said mounting means including a pin having a longitudinal axis which is parallel to the direction of movement of the carriage and on which the switching bar is mounted for pivotal movement, about such longitudinal axis, from said rest position; and a switching lever which is mounted to the machine for movement in a direction parallel to the direction of movement of the carriage to deactivate a carriage return drive, said push rod engaging said switching lever after said blocking member has engaged said stop means for deactivating the carriage return drive during said displacement.

2. An apparatus as defined in claim 1, wherein said stop means includes a plurality of stop members, said blocking member is constructed of a synthetic material having good noise damping characteristics and has a plurality of open slots forming a comb-shaped structure engageable with said plurality of stop members, and said stop means extend across the entire operating width of the machine for engagement along any point of the width with said blocking member. 

1. Apparatus for blocking the movement of the carriage of typewriters and similar machines during the performance of line shifts, comprising: carriage stop means mounted to the carriage; a switching bar provided with a push rod extending outwardly in the direction of movement of the carriage and a blocking member having an open slot; means for biasing said switching bar into a rest position; connecting means connected to said switching bar and operatively connected to a line shift actuator for moving said switching bar away from said rest position and into an operative position and for actuating the carriage return movement; means mounting said switching bar to the machine for a displacement of less than one character space division of the machine in the direction of movement of the carriage and for movement with respect to said stop means into said operative position only when said carriage is stationary for engaging said stop means in said open slot to block the movement of the carriage, said mounting means including a pin having a longitudinal axis which is parallel to the direction of movement of the carriage and on which the switching bar is mounted for pivotal movement, about such longitudinal axis, from said rest position; and a switching lever which is mounted to the machine for movement in a direction parallel to the direction of movement of the carriage to deactivate a carriage return drive, said push rod engaging said switching lever after said blocking member has engaged said stop means for deactivating the carriage return drive during said displacement.
 2. An apparatus as defined in claim 1, wherein said stop means includes a plurality of stop members, said blocking member is constructed of a synthetic material having good noise damping characteristics and has a plurality of open slots forming a comb-shaped structure engageable with said plurality of stop members, and said stop means extend across the entire operating width of the machine for engagement along any point of the width with said blocking member. 